Chlorophyll: the ubiquitous photocatalyst of nature and its potential as an organo-photocatalyst in organic syntheses.

Chlorophyll, the principal photoacceptor of green plants, plays a pivotal role in photosynthesis. In the recent past, chlorophyll has also been utilized as an efficient organo-photocatalyst in several organic syntheses. The inexpensive, ubiquitous nature of chlorophyll endorses it as an appealing green alternative to transition metal photocatalysts. This review is the first attempt to showcase and analyze the photocatalytic activity of chlorophyll in effecting different organic transformations. We intend to provide a holistic overview of the role of chlorophyll starting from photosynthesis to its contemporary synthetic applications in visible light photocatalysis. In addition, the photophysical and electrochemical properties of chlorophyll are elaborated to attain a clearer understanding of its mode of action as a visible light photocatalyst.

Harnessing selective PET and EnT catalysis by chlorophyll to synthesize N-alkylated quinoline-2(1H)-ones, isoquinoline-1(2H)-ones and 1,2,4-trioxanes.

Photocatalytic syntheses of quinoline-2(1H)-ones, isoquinoline-1(2H)-ones and 1,2,4-trioxanes were achieved by selective photo-induced electron transfer (PET) and energy transfer (EnT), respectively, by chlorophyll under visible light irradiation. Quinoline-2(1H)-ones, isoquinoline-1(2H)-ones and 1,2,4-trioxanes are biologically potent scaffolds and their syntheses following mild reaction protocols are highly sought after. This work showcases the divergent photocatalytic roles of chlorophyll viz., electron transfer in the case of quinolines or isoquinolines and energy transfer with allyl alcohols as substrates, affording their aerobic oxidation under green reaction conditions. The mechanistic investigations affirm that the catalytic cycle follows the electron-transfer pathway in carrying out the oxidation of N-alkyl(iso)quinolinium salts. Furthermore, the method provides an environmentally benign, simple reaction strategy for organic transformations of (N)-heterocycles.

Severity of alcoholism in Indian males: Correlation with age of onset and family history of alcoholism.

BACKGROUND: Family History of Alcoholism and earlier Age of Onset are found to predict Severity of alcoholism. Previous Indian studies in this regard have methodological issues related to the definition of alcoholism and reliability of information obtained. AIMS: To study the relationship between the Age of onset/Family History and Severity of alcoholism. SETTINGS AND DESIGN: Consecutively admitted, 20 to 50 year old men, with alcohol-related problems at an urban teaching hospital, were recruited. MATERIALS AND METHODS: After detoxification, alcohol use detection inventory test, severity of alcohol dependence questionnaire, schedule for clinical assessment in neuropsychiatry, and family interview for genetic studies were administered. Family history density was computed. STATISTICS: Pearson's correlations, linear regression, and ANOVA tests were used. RESULTS: Family history density and severity of alcoholism were positively correlated. Age of onset of initiation had a significant negative correlation with severity. The effect of family history on the rapidity of development of Problem-drinking did not reach statistical significance among those with early age of onset. The variance explained by the 'family history status' and 'age of onset' for the severity of alcoholism was similar to that reported in earlier western studies. CONCLUSION: This study, with enhanced methodology, using a general hospital sample of problem drinkers concludes that the age of onset of initiation is a better predictor of severity of alcoholism, than family history of alcoholism alone. Postponing the use of alcohol till the age of 25 years could be explored as a primary prevention strategy in genetically vulnerable adolescents.